​Use of Defoliants for Achieving Improved Productivity and Quality of Cotton: A Review

Cotton is one of the most important cash crop grown for its fibre, which is the raw material for the textile industry. In India, the average yield and profitability of cotton cultivation are low as compared to developing countries. The main reason for this is hand picking of bolls, which is labour intensive resulting into low income of cotton growers. Furthermore, in India, most of the cotton varieties are indeterminate where the bolls do not mature at the same time and thus requires repeated hand pickings. Whereas the developed countries have 100% mechanized cotton picking due to determinate or semi-determinate plant types. Adoption of mechanical harvesting in India is dependent upon the availability of suitable cotton varieties as well as defoliants, desiccants, boll openers, growth hormones and re-growth inhibitors (Thatikunta et al., 2018). Defoliation before cotton harvesting is very important to maintain the quality of produce. In this paper, a comprehensive review is presented on effect and timing of application of defoliants on physiological characteristics of cotton. This will help in developing further research proposals to develop plant types for mechanical harvesting and use of defoliates to produce good fiber quality and increased farm income.